diff options
Diffstat (limited to 'hash.h')
| -rw-r--r-- | hash.h | 85 |
1 files changed, 85 insertions, 0 deletions
@@ -1,6 +1,8 @@ #ifndef HASH_H #define HASH_H +#include "git-compat-util.h" + #if defined(SHA1_PPC) #include "ppc/sha1.h" #elif defined(SHA1_APPLE) @@ -13,4 +15,87 @@ #include "block-sha1/sha1.h" #endif +#ifndef platform_SHA_CTX +/* + * platform's underlying implementation of SHA-1; could be OpenSSL, + * blk_SHA, Apple CommonCrypto, etc... Note that the relevant + * SHA-1 header may have already defined platform_SHA_CTX for our + * own implementations like block-sha1 and ppc-sha1, so we list + * the default for OpenSSL compatible SHA-1 implementations here. + */ +#define platform_SHA_CTX SHA_CTX +#define platform_SHA1_Init SHA1_Init +#define platform_SHA1_Update SHA1_Update +#define platform_SHA1_Final SHA1_Final +#endif + +#define git_SHA_CTX platform_SHA_CTX +#define git_SHA1_Init platform_SHA1_Init +#define git_SHA1_Update platform_SHA1_Update +#define git_SHA1_Final platform_SHA1_Final + +#ifdef SHA1_MAX_BLOCK_SIZE +#include "compat/sha1-chunked.h" +#undef git_SHA1_Update +#define git_SHA1_Update git_SHA1_Update_Chunked +#endif + +/* + * Note that these constants are suitable for indexing the hash_algos array and + * comparing against each other, but are otherwise arbitrary, so they should not + * be exposed to the user or serialized to disk. To know whether a + * git_hash_algo struct points to some usable hash function, test the format_id + * field for being non-zero. Use the name field for user-visible situations and + * the format_id field for fixed-length fields on disk. + */ +/* An unknown hash function. */ +#define GIT_HASH_UNKNOWN 0 +/* SHA-1 */ +#define GIT_HASH_SHA1 1 +/* Number of algorithms supported (including unknown). */ +#define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1) + +/* A suitably aligned type for stack allocations of hash contexts. */ +union git_hash_ctx { + git_SHA_CTX sha1; +}; +typedef union git_hash_ctx git_hash_ctx; + +typedef void (*git_hash_init_fn)(git_hash_ctx *ctx); +typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len); +typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx); + +struct git_hash_algo { + /* + * The name of the algorithm, as appears in the config file and in + * messages. + */ + const char *name; + + /* A four-byte version identifier, used in pack indices. */ + uint32_t format_id; + + /* The length of the hash in binary. */ + size_t rawsz; + + /* The length of the hash in hex characters. */ + size_t hexsz; + + /* The hash initialization function. */ + git_hash_init_fn init_fn; + + /* The hash update function. */ + git_hash_update_fn update_fn; + + /* The hash finalization function. */ + git_hash_final_fn final_fn; + + /* The OID of the empty tree. */ + const struct object_id *empty_tree; + + /* The OID of the empty blob. */ + const struct object_id *empty_blob; +}; +extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS]; + #endif |